The present invention relates to a safety valve assembly for pressure medium-operated consumer devices, particularly clutch and brake devices for presses. More particularly, it relates to a safety valve assembly which has two valves operating in parallel with one another and each having a working piston and a valve member, the valve members correspondingly controlling the connections between a supply inlet, a consumer outlet and a return outlet provided in the housing of the assembly.
Safety valve assemblies of the above-mentioned general type are known in the art. In a known safety valve assembly disclosed in the German application Ser. No. 2,756,240.9, the valve members are guided in chambers of the housing which communicate with one another by cross-passages, wherein each of the cross-passages extends from the supply side of one chamber to the discharge side of the other chamber to the point located upstream of a respective one of the valve seats of the valves. In the above-mentioned safety valve assembly, no residual pressure takes place in the consumer outlet in the event of malfunction of one of the valves. In order to monitor the position of the valve, a pressure switch is provided which compares the pressure in the cross-passages with the supply pressure and actuates a respective electric switch in the event of deviation of pressure in the passages. The electric switch, in turn, turns off the entire assembly. The monitoring which is performed in this safety valve assembly is relatively complicated, to some extent.